Mode I fracture toughness of asymmetric metal-composite adhesive joints

In this work, the mode I fracture toughness of dissimilar metal-composite adhesive joints is experimentally investigated using double cantilever beam (DCB) test. The particular joint under study resulted by joining a thin titanium sheet with carbon fiber reinforced plastic (CFRP) laminate and envisioned to be implemented in hybrid laminar flow control system future aircraft. Four different industrial technologies for CFRP adherents are evaluated/compared; co-bonding without secondary bonding either thermoset or thermoplastic CFRP. vacuum-assisted resin transfer molding (VARTM) technique employed manufacturing panels. After manufacturing, panels cut into test specimens that, because they too (approximately 2.4 mm thick), needed stiffened from both composite sides two aluminum backing beams ensure non-yielding during subsequent DCB tests. Towards determination experimental data, an analytical model recently developed authors, that considers bending-extension coupling sub-laminates constituting specimen as well manufacturing-induced residual thermal stresses, applied. For four options (MO) investigated, load-displacement behaviors, failure patterns, performances presented compared.